In order to maintain adequate traction for thoroughfares, such as roadways, runways, highways, ramps, walkways, etc., agencies frequently spread a gritty material upon the surfaces.
Typically, sand, gravel, cinders, stone, chips, etc., are spread on thoroughfares at varying rates to provide traction on slippery pavements.
A major drawback with many traction enhancers occurs when vehicles travel continuously over the treated roadway; the traction control agents are ground finer and finer leading to increased airborne particulate pollution.
In particular, several areas of Colorado are in violation of the National and State Ambient Air Quality Standard for particles less than or equal to 10 .mu.m in diameter ("PM.sub.10 "). One source of PM.sub.10 emissions is the resuspension of antiskid material applied to active roads. Previous studies have established a direct relationship between the loading of materials on paved surfaces and the PM.sub.10 emissions generated by vehicular traffic. Furthermore, emissions from street sanding have been shown to contribute up to forty-five percent of many of the maximum winter concentrations in Denver.
It is clear from studies cited in "Guidance Document of Selecting Antiskid Materials Applied to Ice-and-Snow-Covered Roadways" (U.S. Environmental Protection Agency--1991) that techniques for controlling PM.sub.10 emissions resulting from antiskid materials should be aimed at minimizing small particle size loadings on the traveled portions of the roadway. Specifically, reduced silt loadings may be expected to result from snow/ice control programs that encompass improvements in three areas: (1) the properties of antiskid materials applied, (2) the application protocols and procedures, and (3) the procedures for removal of the antiskid material from roadways.
The goal for controlling PM.sub.10 concentration is in the reduction of fine particulate emissions. Emission reductions may result from: (1) the use of antiskid materials that have been tested for durability and silt content, (2) lower application rates and application of the material on fewer roads, and (3) removal of material through wet or dry broom sweeping, vacuuming, or water flushing.